US20060228077A1 - Rosa alignment using dc or low frequency optical source - Google Patents
Rosa alignment using dc or low frequency optical source Download PDFInfo
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- US20060228077A1 US20060228077A1 US11/092,443 US9244305A US2006228077A1 US 20060228077 A1 US20060228077 A1 US 20060228077A1 US 9244305 A US9244305 A US 9244305A US 2006228077 A1 US2006228077 A1 US 2006228077A1
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- Prior art keywords
- photodiode
- barrel
- current
- receptacle
- fiber
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/24—Coupling light guides
- G02B6/42—Coupling light guides with opto-electronic elements
- G02B6/4201—Packages, e.g. shape, construction, internal or external details
- G02B6/4219—Mechanical fixtures for holding or positioning the elements relative to each other in the couplings; Alignment methods for the elements, e.g. measuring or observing methods especially used therefor
- G02B6/422—Active alignment, i.e. moving the elements in response to the detected degree of coupling or position of the elements
- G02B6/4225—Active alignment, i.e. moving the elements in response to the detected degree of coupling or position of the elements by a direct measurement of the degree of coupling, e.g. the amount of light power coupled to the fibre or the opto-electronic element
Definitions
- the invention generally relates to aligning optical components. More specifically, the invention relates to aligning a TO can, including a photodiode, in a receptacle.
- Fiber-optic communication is used to transmit digital signals.
- the signals are converted to and from light signals which are then transmitted and received along fiber-optic cables.
- the fiber-optic cables are generally glass and/or plastic waveguides that allow for the propagation of optical signals along the fiber-optic cables.
- a light emitting diode (LED) or laser is often used to convert the digital signal to an optical signal.
- the LED or laser is often included in an optical component known as a transmitting optical subassembly (TOSA).
- TOSA transmitting optical subassembly
- the TOSA modulates the laser according to a digital electronic stream received at the TOSA to produce a modulated optical signal.
- This modulated optical signal is sent along a fiber-optic cable to a receiver optical subassembly (ROSA).
- ROSA receiver optical subassembly
- a ROSA generally includes a photodiode or other light-sensitive device connected to a transimpedance amplifier (TIA).
- TIA transimpedance amplifier
- Light from the optical signal impinging the photodiode causes a current to pass through the photodiode where the current corresponds to the amount of light impinging the photodiode.
- the TIA converts the current running through the photodiode to an electronic signal usable by a digital device such as a computer, network router and the like.
- the TOSA and ROSA often include fixed receptacles, such as LC, SC and the like, that allow the fiber-optic cables to be plugged into the receptacle such that the fiber-optic cables are properly aligned for receiving and delivering optical signals.
- fixed receptacles such as LC, SC and the like
- the photodiode is often encapsulated in a transistor outline (TO) can where the TO can also encapsulates supporting circuitry for the photodiode such as the TIA.
- the TO can often includes a transparent top surface for receiving optical signals at the photodiode.
- a high frequency optical signal is directed into the receptacle while the TO can is manipulated in the barrel of the receptacle until the highest amount of coupling of the optical signal into the photodiode occurs.
- the TO may then be epoxied or otherwise fixed in the barrel of the receptacle such that it is in an optimum position for receiving optical signals.
- the ROSA may be designed to receive optical signals that are in the 1 gigabit per second and higher range. Alignment techniques have typically used a 1 gigabit per second or higher signal directed into the photodiode to align the TO can in the barrel for maximum optical coupling. Unfortunately, expensive test equipment must be used to monitor the signal in the ROSA for determining when the maximum optical coupling occurs because of the high frequencies used when aligning.
- test equipment that can test ROSA alignment using lower frequency or DC optical signals.
- Embodiments are directed towards aligning TO cans in receptacles.
- the TO cans may include a photodiode.
- the embodiments allow low frequency or DC optical signals to be used to align the TO cans in the receptacles.
- Current is monitored through the photodiode, or alternatively a Received Signal Strength Indicator (RSSI) output of a transimpedance amplifier is monitored to determine when a photodiode in a TO can is receiving a maximum amount of optical power.
- RSSI Received Signal Strength Indicator
- a method of aligning a TO can in a receptacle includes a fiber receptacle for receiving a fiber and a barrel for receiving a TO can.
- the TO can includes a photodiode connected to a transimpedance amplifier.
- the photodiode has a node that is accessible external to the TO can.
- the method includes connecting the photodiode to a source external to the TO can.
- the transimpedance amplifier is connected to a source.
- a low frequency beam is directed into the fiber receptacle.
- the TO can is manipulated in the barrel. Current through the photodiode is monitored as the TO can is manipulated.
- the TO can is fixed in the barrel in a position where current through the photodiode is at a maximum or at a predetermined threshold.
- a method of aligning a TO can is performed on a TO can with a photodiode and transimpedance amplifier, where the transimpedance amplifier includes an RSSI output.
- the TO can is aligned in a receptacle that includes a fiber receptacle for receiving a fiber and a barrel for receiving the TO can.
- the method includes connecting the transimpedance amplifier to a source. A low frequency beam is directed into the fiber receptacle.
- the TO can is selectively manipulated in the barrel.
- the RSSI output is monitored as the TO can is selectively manipulated.
- the TO is fixed in the barrel in a position where the RSSI output is at a maximum or at a predetermined threshold.
- the alignment apparatus includes an optical power source.
- the optical power source is able to be connected to a fiber receptacle.
- a low frequency supply is connected to the optical power source.
- a first external supply is able to connect to a transimpedance amplifier in a TO can.
- Such a transimpedance amplifier is typically connected to a photodiode.
- a second external supply is able to connect to the photodiode for supplying current to the photodiode.
- An amplifier is able to connect to the photodiode. The amplifier outputs a signal proportional to current through the photodiode.
- a test fixture is connected to the amplifier. The test fixture is able to monitor the signal proportional to current through the photodiode.
- the test fixture includes an indicator that indicates when the photodiode in the TO can has a maximum current or predetermined threshold of current passing through the photodiode.
- Another alignment apparatus includes an optical power source that can be connected to a fiber receptacle.
- the optical power source is connected to a low frequency supply.
- An external supply is able to connect to a transimpedance amplifier.
- the transimpedance amplifier may be disposed in a TO can and connected to a photodiode that is also disposed in the TO can.
- a test fixture is able to connect to an RSSI output of the transimpedance amplifier.
- the test fixture is configured to monitor the RSSI output.
- the test fixture includes an indicator that is able to indicate when the RSSI output is at a maximum or a predetermined threshold.
- the embodiments described above facilitate alignment of TO cans with photodiodes in receptacles without using high frequency signals for which the TO cans are typically used with. This allows for less expensive equipment to be used in the alignment process.
- FIG. 1 illustrates a TO can being aligned in an LC receptacle
- FIG. 2 illustrates a schematic representation of a circuit used for aligning a TO can in a receptacle
- FIG. 3 illustrates a schematic representation of an alternate circuit used for aligning a TO can in a receptacle.
- Some embodiments of the present invention make use of direct access to photodiodes in ROSAs or access to a Received Signal Strength Indicator (RSSI) output from a transimpedance amplifier (TIA).
- RSSI Received Signal Strength Indicator
- TIA transimpedance amplifier
- the LC receptacle 104 includes a fiber receptacle 106 and a barrel 108 .
- the fiber receptacle 106 is adapted to receive a fiber-optic cable for transmitting optical signals into the LC receptacle 104 .
- the barrel 108 is adapted to receive a TO can 102 .
- the TO can 102 is aligned in the barrel 108 such that maximum coupling of an optical signal received from a fiber-optic cable in the fiber receptacle 106 is achieved in the photodiode in the TO can 102 .
- One embodiment allows an optical source 112 powered by a DC supply 114 to transmit an optical beam through a fiber 116 in the fiber receptacle 106 into the barrel 108 , further into the TO can 102 where the optical beam may be received by a photodiode in the TO can 102 .
- An external pin 110 that is connected to circuitry within the TO can 102 is connected to the photodiode or to an RSSI output of a TIA. This allows circuitry external to the TO can 102 to monitor the amount of optical power received by the photodiode in the TO can 102 .
- a method is used whereby the TO can 102 is manipulated in the barrel 108 while a DC powered optical source beam is fed into the fiber receptacle 106 .
- the TO can 102 may be fixed in the barrel 108 in the position where maximum coupling or the predetermined threshold was reached.
- FIG. 2 a schematic diagram of circuitry used in implementing the method described in FIG. 1 shown.
- FIG. 2 illustrates a TIA 202
- TIA 202 includes a supply node 204 that is adapted to be connected to an external power supply.
- the TIA 202 further includes a ground connection 206 .
- the TIA 202 is connected to a photodiode 208 . When light impinges the photodiode 208 , the TIA 202 produces an electrical signal at the differential output nodes 210 .
- the photodiode 208 is connected to an external photodiode node 212 .
- an external supply 216 may be connected to a current sensing resistor 214 which is in turn connected to the photodiode 208 .
- a voltage produced at the external photodiode node 212 is produced when current flows through the current sensing resistor 214 and the photodiode 208 .
- the amount of current passing through the resistor 214 and photodiode 208 can be calculated from the value of the resistor 214 and the difference in voltages at the external supply 216 and the external photodiode node 212 .
- the voltage produced at the external photodiode node 212 may be fed into a high precision amplifier 218 .
- the amplifier 218 is a high gain high precision amplifier. Further, high precision resistors or other components may be used to appropriately bias the amplifier 218 .
- Amplifier 218 is designed to output a particular voltage at an output node 220 where the particular voltage is dependent on the amount of current running through the resistor 214 and photodiode 208 .
- the output of the amplifier 218 may be designed to produce an output voltage in the range of 0 to 10 V. The range may be dependent on other equipment that will use the output voltage.
- the output voltage node 220 is connected to a test fixture 222 .
- the test fixture 222 may include circuitry that requires input voltages to be within a certain range.
- the output of the amplifier 218 can be designed to appropriately match the input requirements of the test fixture 222 .
- the output voltage in one embodiment, may be 0.5 V at dark current (i.e. the current running through the photodiode 208 when no light is impinging the photodiode 208 ) and 10 V at the highest expected current through the photodiode 208 .
- the test fixture 222 may include an indicator that indicates the amount of coupling of light to the photodiode 208 . Using this indicator, it can be determined when the maximum amount of coupling occurs or when the predetermined threshold of light is coupled into the photodiode 208 . Thus, the indicator may be used to determine when a TO can 102 ( FIG. 1 ) should be secured in place in the barrel 108 ( FIG. 1 ) of an LC receptacle 104 ( FIG. 1 ).
- the indicator as used herein may be embodied in several different forms. For example, the indicator may be an indicator such as an analog or digital meter output. Alternatively, various alarms, whether audio, visual, or otherwise may be used. Further, in some embodiments, the indicator may be a digital or analog signal that may be received by a computer or other electronic circuit.
- test fixture 222 may include computer controlled robotics to adjust the TO can 102 ( FIG. 1 ) and to secure the TO can 102 ( FIG. 1 ) in the barrel 108 ( FIG. 1 ) when maximum or a sufficient amount of coupling occurs.
- a TIA 302 is connected to a test fixture 322 by an RSSI output 350 .
- the RSSI output 350 in a TIA 302 is used to determine the average power received at the TIA 302 .
- the RSSI output 350 can be used to detect a DC powered light source directing optical energy into a photodiode 308 . When light impinging the photodiode 308 is at a maximum or above a predetermined threshold as a result of manipulating a TO can 102 ( FIG. 1 ) in a barrel 108 ( FIG. 1 ) of an LC receptacle 104 ( FIG.
- the output at the RSSI output 350 may be used to so indicate such as when that output is fed into a test fixture 322 .
- the TIA 302 includes a differential output 310 , a supply node 304 , and a ground connection 306 .
- embodiments of the present invention indicate that a DC powered optical source is used to align a TO can in the barrel of an LC receptacle
- other embodiments of the invention may allow for the use of other signals.
- an optical signal at a lower frequency than the signals typically used in ROSAs i.e. one gigabit per second and above
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- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Couplings Of Light Guides (AREA)
- Light Receiving Elements (AREA)
Abstract
Description
- 1. The Field of the Invention
- The invention generally relates to aligning optical components. More specifically, the invention relates to aligning a TO can, including a photodiode, in a receptacle.
- 2. Description of the Related Art
- Fiber-optic communication is used to transmit digital signals. The signals are converted to and from light signals which are then transmitted and received along fiber-optic cables. The fiber-optic cables are generally glass and/or plastic waveguides that allow for the propagation of optical signals along the fiber-optic cables.
- A light emitting diode (LED) or laser is often used to convert the digital signal to an optical signal. The LED or laser is often included in an optical component known as a transmitting optical subassembly (TOSA). The TOSA modulates the laser according to a digital electronic stream received at the TOSA to produce a modulated optical signal. This modulated optical signal is sent along a fiber-optic cable to a receiver optical subassembly (ROSA).
- A ROSA generally includes a photodiode or other light-sensitive device connected to a transimpedance amplifier (TIA). Light from the optical signal impinging the photodiode causes a current to pass through the photodiode where the current corresponds to the amount of light impinging the photodiode. The TIA converts the current running through the photodiode to an electronic signal usable by a digital device such as a computer, network router and the like.
- It is desirable to manufacture TOSAs and ROSAs such that they can be implemented quickly and efficiently in an optical network. Thus, the TOSA and ROSA often include fixed receptacles, such as LC, SC and the like, that allow the fiber-optic cables to be plugged into the receptacle such that the fiber-optic cables are properly aligned for receiving and delivering optical signals.
- In the example of a ROSA, the photodiode is often encapsulated in a transistor outline (TO) can where the TO can also encapsulates supporting circuitry for the photodiode such as the TIA. The TO can often includes a transparent top surface for receiving optical signals at the photodiode. To couple a receptacle to the TO can, a high frequency optical signal is directed into the receptacle while the TO can is manipulated in the barrel of the receptacle until the highest amount of coupling of the optical signal into the photodiode occurs. The TO can may then be epoxied or otherwise fixed in the barrel of the receptacle such that it is in an optimum position for receiving optical signals.
- The ROSA may be designed to receive optical signals that are in the 1 gigabit per second and higher range. Alignment techniques have typically used a 1 gigabit per second or higher signal directed into the photodiode to align the TO can in the barrel for maximum optical coupling. Unfortunately, expensive test equipment must be used to monitor the signal in the ROSA for determining when the maximum optical coupling occurs because of the high frequencies used when aligning.
- What would be useful is test equipment that can test ROSA alignment using lower frequency or DC optical signals.
- Embodiments are directed towards aligning TO cans in receptacles. The TO cans may include a photodiode. The embodiments allow low frequency or DC optical signals to be used to align the TO cans in the receptacles. Current is monitored through the photodiode, or alternatively a Received Signal Strength Indicator (RSSI) output of a transimpedance amplifier is monitored to determine when a photodiode in a TO can is receiving a maximum amount of optical power.
- For example, in one embodiment, a method of aligning a TO can in a receptacle is described. The receptacle includes a fiber receptacle for receiving a fiber and a barrel for receiving a TO can. The TO can includes a photodiode connected to a transimpedance amplifier. The photodiode has a node that is accessible external to the TO can. The method includes connecting the photodiode to a source external to the TO can. The transimpedance amplifier is connected to a source. A low frequency beam is directed into the fiber receptacle. The TO can is manipulated in the barrel. Current through the photodiode is monitored as the TO can is manipulated. The TO can is fixed in the barrel in a position where current through the photodiode is at a maximum or at a predetermined threshold.
- In another embodiment, a method of aligning a TO can is performed on a TO can with a photodiode and transimpedance amplifier, where the transimpedance amplifier includes an RSSI output. The TO can is aligned in a receptacle that includes a fiber receptacle for receiving a fiber and a barrel for receiving the TO can. The method includes connecting the transimpedance amplifier to a source. A low frequency beam is directed into the fiber receptacle. The TO can is selectively manipulated in the barrel. The RSSI output is monitored as the TO can is selectively manipulated. The TO can is fixed in the barrel in a position where the RSSI output is at a maximum or at a predetermined threshold.
- One embodiment is directed towards an alignment apparatus. The alignment apparatus includes an optical power source. The optical power source is able to be connected to a fiber receptacle. A low frequency supply is connected to the optical power source. A first external supply is able to connect to a transimpedance amplifier in a TO can. Such a transimpedance amplifier is typically connected to a photodiode. A second external supply is able to connect to the photodiode for supplying current to the photodiode. An amplifier is able to connect to the photodiode. The amplifier outputs a signal proportional to current through the photodiode. A test fixture is connected to the amplifier. The test fixture is able to monitor the signal proportional to current through the photodiode. The test fixture includes an indicator that indicates when the photodiode in the TO can has a maximum current or predetermined threshold of current passing through the photodiode.
- Another alignment apparatus includes an optical power source that can be connected to a fiber receptacle. The optical power source is connected to a low frequency supply. An external supply is able to connect to a transimpedance amplifier. The transimpedance amplifier may be disposed in a TO can and connected to a photodiode that is also disposed in the TO can. A test fixture is able to connect to an RSSI output of the transimpedance amplifier. The test fixture is configured to monitor the RSSI output. The test fixture includes an indicator that is able to indicate when the RSSI output is at a maximum or a predetermined threshold.
- Advantageously, the embodiments described above facilitate alignment of TO cans with photodiodes in receptacles without using high frequency signals for which the TO cans are typically used with. This allows for less expensive equipment to be used in the alignment process.
- These and other advantages and features of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.
- In order that the manner in which the above-recited and other advantages and features of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
-
FIG. 1 illustrates a TO can being aligned in an LC receptacle; -
FIG. 2 illustrates a schematic representation of a circuit used for aligning a TO can in a receptacle; and -
FIG. 3 illustrates a schematic representation of an alternate circuit used for aligning a TO can in a receptacle. - Some embodiments of the present invention make use of direct access to photodiodes in ROSAs or access to a Received Signal Strength Indicator (RSSI) output from a transimpedance amplifier (TIA). With direct access to the photodiode or access to the RSSI output from the transimpedance amplifier, low frequency currents and voltages including DC currents and voltages, can be used to align a TO can in a receptacle.
- Referring now to
FIG. 1 , an example of a method for aligning a TO can 102 that includes a photodiode and transimpedance amplifier, in anLC receptacle 104 is shown. TheLC receptacle 104 includes afiber receptacle 106 and abarrel 108. Thefiber receptacle 106 is adapted to receive a fiber-optic cable for transmitting optical signals into theLC receptacle 104. Thebarrel 108 is adapted to receive a TO can 102. Optimally, the TO can 102 is aligned in thebarrel 108 such that maximum coupling of an optical signal received from a fiber-optic cable in thefiber receptacle 106 is achieved in the photodiode in the TO can 102. - One embodiment allows an
optical source 112 powered by aDC supply 114 to transmit an optical beam through afiber 116 in thefiber receptacle 106 into thebarrel 108, further into the TO can 102 where the optical beam may be received by a photodiode in the TO can 102. Anexternal pin 110 that is connected to circuitry within the TO can 102 is connected to the photodiode or to an RSSI output of a TIA. This allows circuitry external to the TO can 102 to monitor the amount of optical power received by the photodiode in the TO can 102. Thus, in one embodiment, a method is used whereby the TO can 102 is manipulated in thebarrel 108 while a DC powered optical source beam is fed into thefiber receptacle 106. When measurements at theexternal pin 110 indicate that coupling of the optical source beam is at a maximum or above a predetermined threshold, the TO can 102 may be fixed in thebarrel 108 in the position where maximum coupling or the predetermined threshold was reached. - Referring now
FIG. 2 , a schematic diagram of circuitry used in implementing the method described inFIG. 1 shown.FIG. 2 illustrates aTIA 202TIA 202 includes asupply node 204 that is adapted to be connected to an external power supply. TheTIA 202 further includes aground connection 206. TheTIA 202 is connected to aphotodiode 208. When light impinges thephotodiode 208, theTIA 202 produces an electrical signal at thedifferential output nodes 210. - In the example shown, the
photodiode 208 is connected to anexternal photodiode node 212. In the present example, anexternal supply 216 may be connected to acurrent sensing resistor 214 which is in turn connected to thephotodiode 208. A voltage produced at theexternal photodiode node 212 is produced when current flows through thecurrent sensing resistor 214 and thephotodiode 208. Using Ohms law, the amount of current passing through theresistor 214 andphotodiode 208 can be calculated from the value of theresistor 214 and the difference in voltages at theexternal supply 216 and theexternal photodiode node 212. The voltage produced at theexternal photodiode node 212 may be fed into ahigh precision amplifier 218. In one embodiment, theamplifier 218 is a high gain high precision amplifier. Further, high precision resistors or other components may be used to appropriately bias theamplifier 218. -
Amplifier 218 is designed to output a particular voltage at anoutput node 220 where the particular voltage is dependent on the amount of current running through theresistor 214 andphotodiode 208. In one example, the output of theamplifier 218 may be designed to produce an output voltage in the range of 0 to 10 V. The range may be dependent on other equipment that will use the output voltage. For example, as shown inFIG. 2 theoutput voltage node 220 is connected to atest fixture 222. Thetest fixture 222 may include circuitry that requires input voltages to be within a certain range. Thus the output of theamplifier 218 can be designed to appropriately match the input requirements of thetest fixture 222. Thus, the output voltage, in one embodiment, may be 0.5 V at dark current (i.e. the current running through thephotodiode 208 when no light is impinging the photodiode 208) and 10 V at the highest expected current through thephotodiode 208. - The
test fixture 222 may include an indicator that indicates the amount of coupling of light to thephotodiode 208. Using this indicator, it can be determined when the maximum amount of coupling occurs or when the predetermined threshold of light is coupled into thephotodiode 208. Thus, the indicator may be used to determine when a TO can 102 (FIG. 1 ) should be secured in place in the barrel 108 (FIG. 1 ) of an LC receptacle 104 (FIG. 1 ). The indicator as used herein may be embodied in several different forms. For example, the indicator may be an indicator such as an analog or digital meter output. Alternatively, various alarms, whether audio, visual, or otherwise may be used. Further, in some embodiments, the indicator may be a digital or analog signal that may be received by a computer or other electronic circuit. - This process may be automated or performed manually. For example, the
test fixture 222 may include computer controlled robotics to adjust the TO can 102 (FIG. 1 ) and to secure the TO can 102 (FIG. 1 ) in the barrel 108 (FIG. 1 ) when maximum or a sufficient amount of coupling occurs. - Referring now
FIG. 3 , an alternate embodiment is shown where aTIA 302 is connected to atest fixture 322 by anRSSI output 350. Ordinarily, theRSSI output 350 in aTIA 302 is used to determine the average power received at theTIA 302. However, using principles of embodiments of the present invention, theRSSI output 350 can be used to detect a DC powered light source directing optical energy into aphotodiode 308. When light impinging thephotodiode 308 is at a maximum or above a predetermined threshold as a result of manipulating a TO can 102 (FIG. 1 ) in a barrel 108 (FIG. 1 ) of an LC receptacle 104 (FIG. 1 ), the output at theRSSI output 350 may be used to so indicate such as when that output is fed into atest fixture 322. As with the example shown inFIG. 2 , theTIA 302 includes adifferential output 310, asupply node 304, and aground connection 306. - While embodiments of the present invention indicate that a DC powered optical source is used to align a TO can in the barrel of an LC receptacle, other embodiments of the invention may allow for the use of other signals. For example, an optical signal at a lower frequency than the signals typically used in ROSAs (i.e. one gigabit per second and above) may be used to align the TO can in the barrel of a receptacle. This would still allow the alignment be done without using expensive test equipment that is commonly used when higher frequency optical sources are used to direct optical energy into a photodiode.
- While the embodiments described herein have made reference to LC receptacles, other receptacles, such as SC and others, may be used as well. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
Claims (20)
Priority Applications (1)
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US11/092,443 US7140784B2 (en) | 2004-08-31 | 2005-03-29 | Rosa alignment using DC or low frequency optical source |
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US60609604P | 2004-08-31 | 2004-08-31 | |
US11/092,443 US7140784B2 (en) | 2004-08-31 | 2005-03-29 | Rosa alignment using DC or low frequency optical source |
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US20060228077A1 true US20060228077A1 (en) | 2006-10-12 |
US7140784B2 US7140784B2 (en) | 2006-11-28 |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9847434B2 (en) * | 2015-03-23 | 2017-12-19 | Applied Optoelectronics, Inc. | Multichannel receiver optical subassembly with improved sensitivity |
Citations (5)
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US6265240B1 (en) * | 1998-03-24 | 2001-07-24 | Lucent Technologies, Inc. | Method and apparatus for passively aligning components on semiconductor dies |
US6325551B1 (en) * | 1999-12-08 | 2001-12-04 | New Focus, Inc. | Method and apparatus for optically aligning optical fibers with optical devices |
US20050023434A1 (en) * | 2003-07-31 | 2005-02-03 | Ler Technologies, Inc. | Electro-optic sensor |
US6861641B1 (en) * | 2002-03-26 | 2005-03-01 | Optical Communication Products, Inc. | Hermetically sealed optical subassembly |
US20050163439A1 (en) * | 2004-01-26 | 2005-07-28 | Vanniasinkam Joseph I. | Optical rosa for long reach optical transceiver |
-
2005
- 2005-03-29 US US11/092,443 patent/US7140784B2/en not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6265240B1 (en) * | 1998-03-24 | 2001-07-24 | Lucent Technologies, Inc. | Method and apparatus for passively aligning components on semiconductor dies |
US6325551B1 (en) * | 1999-12-08 | 2001-12-04 | New Focus, Inc. | Method and apparatus for optically aligning optical fibers with optical devices |
US6861641B1 (en) * | 2002-03-26 | 2005-03-01 | Optical Communication Products, Inc. | Hermetically sealed optical subassembly |
US20050023434A1 (en) * | 2003-07-31 | 2005-02-03 | Ler Technologies, Inc. | Electro-optic sensor |
US20050163439A1 (en) * | 2004-01-26 | 2005-07-28 | Vanniasinkam Joseph I. | Optical rosa for long reach optical transceiver |
Cited By (1)
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US9847434B2 (en) * | 2015-03-23 | 2017-12-19 | Applied Optoelectronics, Inc. | Multichannel receiver optical subassembly with improved sensitivity |
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